A condition that usually happens to parents when they visit their local Wal-mart several times in a 24-hour span. You are on a first name basis with the employees.
Similar to Chronic Targetitis and Chronic Home-Depotitis.
Jill: "Have you seen that matt over there? matt bellamy is hot as."
Jane: " Yah totally, but you're in love with like, every matt. WTF?"
Jill: "oh, that's just my mattitus."
Jane: "..."